The specification relates to real time driving difficulty categorization. The specification may relate to real time driving difficulty categorization for an onboard vision system.
Road driving conditions are dynamic in nature. For example, a roadway may have favorable driving conditions at 2:00 PM and then have less favorable driving conditions as the local time approaches rush hour.
In contrast to road driving conditions, road categorization is static in nature. Each jurisdiction has its own set of hierarchical road classification systems. These systems may classify different roads based the regulatory speed limits and their purpose in traffic engineering. We use this prior road information from the map database, For example, the United States Department of Transportation Federal Highway Administration proposes a functional classification system that categorizes all roads in the United States into three main categories: (1) arterial; (2) collector; and (3) local. An additional category may include a controlled access road. An example a controlled access road is a freeway or interstate. Controlled access roads generally have the highest regulatory speeds. Another category may include a single lane highway. A single lane highway may include a road with relatively high regulatory speeds (though generally not as high as a controlled access road) and no physical boundary between opposing lanes of traffic.
An arterial road includes a high-capacity urban road whose design purpose in traffic engineering includes delivering traffic from a collector road to a controlled access road such as a freeway. Arterial roads may also receive traffic from the controlled access roads and deliver the traffic to a collector road. Arterial roads generally have a higher regulator speed limit than collector roads or local roads.
A collector road includes a low-to-moderate capacity road whose design purpose in traffic engineering includes moving traffic between arterial roads and local roads. Unlike arterial roads, collector roads may be configured to deliver traffic to residential properties. A collector road generally has a lower regulatory speed limit than an arterial road, but a higher regulator speed limit than a local road.
A local road is a low capacity road whose design purpose in traffic engineering is to delivery traffic to residential properties. Local roads generally have lower regulatory speed limits than arterial roads and collector roads.